The present invention relates to a filling valve installed on a filler, and in particular, to a filling valve which is used to fill a carbonated beverage or non-carbonated beverage into a vessel while the mouth of the vessel is sealed by a seal member such as a packing.
A filler generally includes a filling valve comprising a liquid passage for filling formed within a valve housing, a filling nozzle mounted on the downstream end of the liquid passage and a liquid valve which functions to open or close the passage through which the liquid passes, the arrangement being such that the filled liquid is injected into the vessel from the filling nozzle mounted on the downstream end of the liquid passage while the liquid valve is open.
When such a filler is used to fill a vessel with a carbonated beverage, for example, there is a need to close a top end opening of the vessel, and accordingly, a cylindrical elevating member is fitted into the valve housing of the filling valve. A centering guide which guides the top end opening of a vessel is mounted on the elevating member together with a packing which seals the top end opening so that the filling operation takes place while the packing is held pressed against the full perimeter of the top end opening of the vessel to maintain the interior of the vessel sealed. In order to perform the filling operation while the interior of the vessel is maintained in a sealed condition, there must be provided an exhaust passage to exhaust a gas in the vessel. Thus the filling operation of the liquid takes place while exhausting the gas from the vessel through the exhaust passage.
Fillers which perform the filling operation while sealing the mouth of the vessel in a manner mention above are categorized into two types. One of the two filling types is referred to as pressure balanced type (disclosed in Japanese Laid-Open Patent Publication No. 11,989/1996, for example), which is constructed as mentioned below. Specifically, a casing is fixedly mounted on the bottom surface of a filler bowl in an upright manner, and a pipe (a valve stem and a vent tube at the lower end of the stem) is passed through the casing in an elevatable manner. The interior of the pipe defines an exhaust passage while the outside of the pipe serves as a liquid passage for filling, which is opened or closed by a liquid valve. During the filling operation, the vent tube located on the lower end of the valve stem is inserted into the vessel and the liquid valve is opened.
When the liquid valve is opened, the liquid flows into the vessel through the liquid passage and the filling nozzle, while any gas contained within the vessel is discharged into a space above the liquid within the filler bowl through the exhaust passage. When the liquid level of the liquid filled into the vessel rises to block the opening of the exhaust passage and a balance is reached between the pressure within the vessel and the pressure within the filler bowl, the filling operation is completed. A spreader is mounted around the outer periphery of the vent tube to cause the liquid flowing into the vessel to flow along the internal surface of the vessel, thus preventing the liquid flow from bubbling.
A filler according to the other filling type includes a flow meter or a level sensor to detect the filled content, and completes a filling operation when the content reaches a given quantity, thus representing a filled content detection type (disclosed in Japanese Laid-Open Patent Application No. 144,491/1994, for example). A filler disclosed in the second citation includes an annular liquid supply path defined between a housing and an internal piece disposed inside the housing and which is opened or closed by a liquid valve, which is an annular closing element moved up and down in response to a cylinder. The annular liquid supply path has a pouring port, which is conically enlarged downwardly, thus allowing a jet of liquid to be led toward the internal wall of the vessel before flowing down toward the bottom.
A gas passage is formed on the top of the internal piece, and is connected through an exhaust valve to an exhaust chamber and is also connected through a suction valve to a gas space of an annular tank. A liquid level sensor is mounted centrally on the internal piece, and the liquid valve is closed when a distance between the level sensor and the liquid level reaches a given value.
In the arrangement disclosed in the first citation, a liquid to be filled remains within the exhaust passage at the time the filling operation is completed, and must be discharged before the next filling operation can be started. In particular, when a high rate operation is desired, there is a need for the provision of a special discharge mechanism. In addition, the liquid to be filled contacts the vent tube during the filling operation, thus leaving a sanitary problem. Furthermore, when the size or the shape of the vessel is changed, the vent tube which defines the exhaust passage or the spreader must be changed, which is a disadvantage.
In the arrangement disclosed in the second citation, the opening of the exhaust passage is located above the opening of the liquid supply path, and accordingly, the exhaust passage cannot be contacted by the liquid to be filled, and there is no residue of the liquid to be filled within the exhaust passage upon completion of the filling operation. However, in this arrangement, the liquid to be filled flows along the internal wall of the vessel while it is filled, and accordingly, when a canister or a vessel having a flat internal surface around the mouth and a smooth shoulder is to be filled, a bubbling can be suppressed since the liquid to be filled flows along the internal surface of the vessel, but a bubbling is induced by a splashing of the liquid to be filled into a vessel such as a reseal can or a bottle can in which the internal surface around the mouth is formed with an unevenness which corresponds to the configuration of a thread formed around the external surface.
The present invention has been made in order to overcome the described problems and has for its object the provision of a filling valve which is excellent in sanitary performance and which avoids the need of replacement of an attachment for vessels of differing sizes and shapes. It is also an object of the present invention to provide a filling valve which allows a filling operation to take place through the center of a vessel and which allows a stable filling operation which is not influenced by the shape of the vessel.
Above objects are accomplished by providing a filling valve comprising a valve housing internally formed with a liquid passage for filling which communicates with a liquid supply piping for filling and having a filling nozzle at its lower end, a liquid valve for opening or closing the liquid passage, liquid valve elevating means for elevating the liquid valve, seal means mounted on the valve housing for sealing the mouth of a vessel supplied, seal elevating means for elevating the seal means and vessel relative to each other, filled content detecting means for detecting the quantity of liquid which is filled into the vessel, and an exhaust passage formed in the valve housing for exhausting a gas from within the vessel; wherein the exhaust passage has an opening disposed toward the vessel which is disposed outside of an opening of the filling nozzle and the opening of the filling nozzle is maintained above the elevation of the liquid level which is filled into the vessel during the filling operation.
In the filling valve according to the present invention, an opening of the exhaust passage is located outer circumference of the filling nozzle at the end of the filling nozzle, and since the filling nozzle is located inside to allow the liquid filling to take place centrally in the vessel, a stable filling operation can be achieved without being influenced by the shape of the vessel. The opening of the filling nozzle is disposed at an elevation which cannot be contacted by the liquid level of the liquid which is filled into the vessel, thus providing an excellent sanitary achievement. In addition, there is no need of replacing an attachment for vessels of differing sizes and shapes.
A filling valve according to the invention defined in claim 2 is characterized in that the liquid passage for filling is formed with a greater diameter at a location where it communicates with the liquid supply piping for filling in a manner such that the area of the liquid passage at the location having a greater diameter is greater than the liquid channel area of the liquid supply piping for filling, and a restriction is formed downstream of the location having a greater diameter.
In the filling valve according to the invention defined in claim 2, the provision of a portion of the greater diameter at the inlet to the liquid passage for filling from the liquid supply piping for filling moderates the flow of the liquid, and the restriction which is provided downstream thereof also suppresses the flow, thus allowing the liquid which is filled into the vessel to flow gently to prevent a bubbling from occurring if the liquid is not arranged to flow around the internal wall of the vessel.
A filling valve according to the invention defined in claim 3 is characterized in that a straightening vane which straightens the liquid to be filled is provided in the liquid passage for filling at a location upstream of the liquid valve.
In the filling valve according to claim 3, the straightening vane functions to straighten the flow of the liquid to be filled before it is injected into the vessel, thus allowing a smooth filling operation while preventing a bubbling from occurring.
A filling valve according to the invention defined in claim 4 is characterized in that the channel area of the filling nozzle is tapered so that the diameter decreases gradually toward the lower end. When the channel area within the filling nozzle is tapered so that the diameter decreases toward the liquid outlet, the effect of straightening the flow of the liquid to be filled is further improved.